Use of cloprostenol and fluprostenol analogues to treat glaucoma and ocular hypertension

ABSTRACT

Disclosed is the use of cloprostenol and fluprostenol analogues in combination with carbonic anhydrase inhibitors for the treatment of glaucoma and ocular hypertension and ophthalmic compositions therefor.

[0001] The present application is a continuation of U.S. patentapplication Ser. No. 09/281,043, filed Mar. 30, 1999, which is acontinuation-in-part of U.S. patent application Ser. No. 08/917,795,filed Aug. 21, 1997, now U.S. Pat. No. 5,889,052, which is acontinuation of U.S. patent application Ser. No. 08/769,293, filedDec.18, 1996, now U.S. Patent No. 5,665,773, which is a continuation ofU.S. patent application Ser. No. 08/280,681, filed Jul. 26, 1994, nowabandoned, which is a continuation-in-part of U.S. patent applicationSer. No. 08/101,598 filed Aug. 3, 1993, now U.S. Pat. No. 5,510,383.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to the treatment of glaucoma andocular hypertension. In particular, the present invention relates to theuse of cloprostenol and fluprostenol analogues for the treatment ofglaucoma and ocular hypertension.

[0003] Cloprostenol and fluprostenol, both known compounds, aresynthetic analogues of PGF_(2α), a naturally-occurring F-seriesprostaglandin (PG). Structures for PGF_(2α)(I), cloprostenol (II), andfluprostenol (III), are shown below:

[0004] The chemical name for cloprostenol is16-(3-chlorophenoxy)-17,18,19,20-tetranor PGF_(2α). Monograph No. 2397(page 375) of The Merck Index, 11th Edition (1989) is incorporatedherein by reference to the extent that it describes the preparation andknown pharmacological profiles of cloprostenol. Fluprostenol has thechemical name 16-(3-trifluoromethylphenoxy)-17,18,19,20-tetranorPGF_(2α). Monograph No. 4121 (pages 656-657) of The Merck Index, 11thEdition (1989) is incorporated herein by reference to the extent that itdescribes the preparation and known pharmacological profiles offluprostenol. Cloprostenol and fluprostenol are 16-aryloxy PGs and, inaddition to the substituted aromatic ring, differ from the naturalproduct PGF_(2α)in that an oxygen atom is embedded within the lower(omega) chain. This oxygen interruption forms an ether functionality.

[0005] Naturally-occurring prostaglandins are known to lower intraocularpressure (IOP) after topical ocular instillation, but generally causeinflammation, as well as surface irritation characterized byconjunctival hyperemia and edema. Many synthetic prostaglandins havebeen observed to lower intraocular pressure, but such compounds alsoproduce the aforementioned side effects which severely restrict clinicalutility.

SUMMARY OF THE INVENTION

[0006] It has now been unexpectedly found that certain novelcloprostenol and fluprostenol analogues are useful in treating glaucomaand ocular hypertension. In particular, topical application ofophthalmic compositions comprising these novel cloprostenol andfluprostenol analogues result in significant IOP reduction.

DETAILED DESCRIPTION OF THE INVENTION

[0007] The compounds useful in the present invention have the followinggeneral formula:

[0008] wherein:

[0009] R₁═H; C₁-C₁₂ straight-chain or branched alkyl; C₁-C₁₂straight-chain or branched acyl; C₃-C₈ cycloalkyl; or a cationic saltmoiety;

[0010] R₂, R₃═H, or C₁-C₅ straight-chain or branched alkyl; or R₂ and R₃taken together may represent O;

[0011] X═O, S, or CH₂;

[0012] -- represents any combination of a single bond, or a cis or transdouble bond for the alpha (upper) chain; and a single bond or transdouble bond for the omega (lower) chain;

[0013] R₉═H, C₁-C₁₀ straight-chain or branched alkyl, or C₁-C₁₀straight-chain or branched acyl;

[0014] R₁₁═H, C₁-C₁₀ straight-chain or branched alkyl, or C₁-C₁₀straight-chain or branched acyl;

[0015] Y═O; or H and OR₁₅ in either configuration wherein R₁₅═H, C₁-C₁₀straight-chain or branched alkyl, or C₁-C₁₀ straight-chain or branchedacyl; and

[0016] Z═Cl or CF₃; with the proviso that when R₂ and R₃ taken togetherrepresent O, then R₁≠C₁-C₁₂ straight-chain or branched acyl; and whenR₂═R₃═H, then R₁≠a cationic salt moiety.

[0017] The term “acyl” represents a group that is linked by a carbonatom that has a double bond to an oxygen atom and single bond to anothercarbon atom.

[0018] The term “acylamino” represents a group that is linked by anamino atom that is connected to a carbon atom has a double bond to anoxygen group and a single bond to a carbon atom or hydrogen atom.

[0019] The term “acyloxy” represents a group that is linked by an oxygenatom that is connected to a carbon that has a double bond to an oxygenatom and single bond to another carbon atom.

[0020] The term “alkenyl” includes straight or branched chainhydrocarbon groups having 1 to 15 carbon atoms with at least onecarbon-carbon double bond. The chain hydrogens may be substituted withother groups, such as halogen. Preferred straight or branched alkenygroups include, allyl, 1-butenyl, 1-methyl-2-propenyl and 4-pentenyl.

[0021] The term “alkoxy” represents an alkyl group attached through anoxygen linkage.

[0022] The term “alkyl” includes straight or branched chain aliphatichydrocarbon groups that are saturated and have 1 to 15 carbon atoms. Thealkyl groups may be substituted with other groups, such as halogen,hydroxyl or alkoxy. Preferred straight or branched alkyl groups includemethyl, ethyl, propyl, isopropyl, butyl and t-butyl.

[0023] The term “alkylamino” represents an alkyl group attached througha nitrogen linkage.

[0024] The term “alkynyl” includes straight or branched chainhydrocarbon groups having 1 to 15 carbon atoms with at least onecarbon-carbon triple bond. The chain hydrogens may be substituted withother groups, such as halogen. Preferred straight or branched alkynylgroups include, 2-propynyl, 2-butynyl, 3-butynyl, 1-methyl-2-propynyland 2-pentynyl.

[0025] The term “aryl” refers to carbon-based rings which are aromatic.The rings may be isolated, such as phenyl, or fused, such as naphthyl.The ring hydrogens may be substituted with other groups, such as loweralkyl, or halogen.

[0026] The term “carbonyl” represents a group that has a carbon atomthat has a double bond to an oxygen atom.

[0027] The term “carbonylalkoxy” represents a group that is linked by acarbon atom that has a double bond to an oxygen atom and a single bondto an alkoxy group.

[0028] The term “cationic salt moiety” includes alkali and alkalineearth metal salts as well as ammonium salts.

[0029] The term “carbonyloxyl” represents a group that is linked by acarbon atom that has a double bond to an oxygen atom and a single bondto a second oxygen atom.

[0030] The term “cycloalkyl” includes straight or branched chain,saturated or unsaturated aliphatic hydrocarbon groups which connect toform one or more rings, which can be fused or isolated. The rings may besubstituted with other groups, such as halogen, hydroxyl or lower alkyl.Preferred cycloalkyl groups include cyclopropyl, cyclobutyl, cylopentyland cyclohexyl.

[0031] The term “dialkylamino” represents two alkyl groups attachedthrough a nitrogen linkage.

[0032] The term “halogen” and “halo” represents fluoro, chloro, bromo,or iodo.

[0033] The term “heteroaryl” refers to aromatic hydrocarbon rings whichcontain at least one heteroatom such as O, S, or N in the ring.Heteroaryl rings may be isolated, with 5 to 6 ring atoms, or fused, with8 to 10 atoms. The heteroaryl ring(s) hydrogens or heteroatoms with openvalency may be substituted with other groups, such as lower alkyl orhalogen. Examples of heteroaryl groups include imidazole, pyridine,indole, quinoline, furan, thiophene, pyrrole, tetrahydroquinoline,dihydrobenzofuran, and dihydrobenzindole.

[0034] The term “lower alkyl” represents alkyl groups containing one tosix carbons (C₁-C₆).

[0035] Preferred compounds include: cloprostenol isopropyl ester (Table1, compound 1A), fluprostenol isopropyl ester (compound 1B),16-phenoxy-17, 18,19,20-tetranor PGF_(2α)isopropyl ester (compound 2),17-phenyl-18,19,20-trinor PGF_(2α)isopropyl ester (compound 3),13,14-dihydro-17-phenyl-18,19,20-trinor PGF_(2α)) isopropyl ester(compound 4), the 3-oxa form of cloprostenol isopropyl ester (Table 2,compound 5), 13,14-dihydrofluprostenol isopropyl ester (compound 6),cloprostenol-1-ol (compound 7), and 13,14-dihydrocloprostenol-1-olpivaloate (compound 8). TABLE 1 COMPOUND NAME COMPOUND STRUCTURE 1ACloprostenol, isopropyl ester

1B Fluprostenol, isopropyl ester

2 16-Phenoxy-17,18,19,20- tetranor PGF_(2α), isopropyl ester

3 17-Phenyl-18,19,20-trinor PGF_(2α), isopropyl ester

4 13,14-Dihydro-17-phenyl- 18,19,20-trinor PGF_(2α), isopropyl ester

[0036] TABLE 2 COMPOUND NAME COMPOUND STRUCTURE 5 3-oxacloprostenolisopropyl ester

6 13,14-dihydrofluprostenol isopropyl ester

7 cloprostenol-1-ol

8 13,14-dihydrocloprostenol-1-ol pivaloate

[0037] The compounds of formula (IV) are useful in lowering intraocularpressure thus are useful in the treatment of glaucoma. Such compoundsare also useful in improving optic nerve head blood flow and thetreatment of optic nerve disorders (including without limitationretarding visual field loss and improving visual acuity), the latterbeing generally described in U.S. Pat. No. 5,773,471, the contents ofwhich are by this reference incorporated herein. It is furthercontemplated that the compounds of the present inventions can be usedwith other medicaments known to be useful in the treatment of glaucomaor ocular hypertension, either separately or in combination. Forexample, the prostaglandin analogs of the present invention can becombined with (i) beta-blockers, such as timolol, betaxolol, levobunololand the like (see U.S. Pat. No. 4,952,581); (ii) carbonic anhydraseinhibitors, such as brinzolamide; (iii) adrenergic agonists includingclonidine derivatives, such as apraclonidine or brimonidine (see U.S.Pat. No. 5,811,443); and (iv) cholinergic agonists, such as pilocarpine.The disclosures of U.S. Pat. Nos. 4,952,581 and 5,811,443 areincorporated herein by this reference. The preferred route ofadministration is topical. The dosage range for topical administrationis generally between about 0.01 and about 1000 micrograms per eye(μg/eye), preferably between about 0.1 and about 100 μg/eye, and mostpreferably between about 1 and 10 μg/eye. The compounds of the presentinvention can be administered as solutions, suspensions, or emulsions(dispersions) in a suitable ophthalmic vehicle.

[0038] In forming compositions for topical administration, the compoundsof the present invention are generally formulated as between about0.00003 to about 3 percent by weight (wt %) solutions in water at a pHbetween 4.5 to 8.0. The compounds are preferably formulated as betweenabout 0.0003 to about 0.3 wt % and, most preferably, between about 0.003and about 0.03 wt %. While the precise regimen is left to the discretionof the clinician, it is recommended that the resulting solution betopically applied by placing one drop in each eye one or two times aday.

[0039] Other ingredients which may be desirable to use in the ophthalmicpreparations of the present invention include preservatives, co-solventsand viscosity building agents.

[0040] Antimicrobial Preservatives:

[0041] Ophthalmic products are typically packaged in multidose form,which generally require the addition of preservatives to preventmicrobial contamination during use. Suitable preservatives include:benzalkonium chloride, thimerosal, chlorobutanol, methyl paraben, propylparaben, phenylethyl alcohol, edetate disodium, sorbic acid, ONAMER M®),or other agents known to those skilled in the art. Such preservativesare typically employed at a concentration between about 0.001% and about1.0% by weight.

[0042] Co-Solvents:

[0043] Prostaglandins, and particularly ester derivatives, typicallyhave limited solubility in water and therefore may require a surfactantor other appropriate co-solvent in the composition. Such co-solventsinclude: Polysorbate 20, 60 and 80; Pluronic F-68, F-84 and P-103;Tyloxapol®; Cremophor® EL; sodium dodecyl sulfate; glycerol; PEG 400;propylene glycol; cyclodextrins; or other agents known to those skilledin the art. Such co-solvents are typically employed at a concentrationbetween about 0.01% and about 2% by weight.

[0044] Viscosity Agents:

[0045] Viscosity greater than that of simple aqueous solutions may bedesirable to increase ocular absorption of the active compound, todecrease variability in dispensing the formulations, to decreasephysical separation of components of a suspension or emulsion offormulation and/or otherwise to improve the ophthalmic formulation. Suchviscosity building agents include, for example, polyvinyl alcohol,polyvinyl pyrrolidone, methyl cellulose, hydroxy propyl methylcellulose,hydroxyethyl cellulose, carboxymethyl cellulose, hydroxy propylcellulose or other agents known to those skilled in the art. Such agentsare typically employed at a concentration between about 0.01 % and about2% by weight.

[0046] The following Examples 1-4 describe the synthesis of compounds5-8 (Table 2). These syntheses are representative in nature and are notintended to be limiting. Other compounds of formula (IV) may be preparedusing analogous techniques known to those skilled in the art.

[0047] In the examples below, the following standard abbreviations areused: g=grams (mg=milligrams); mol=moles (mmol=millimoles); mol %=molepercent; mL=milliliters; mm Hg=millimeters of mercury; mp=melting point;bp=boiling point; h=hours; and min=minutes. In addition, “NMR” refers tonuclear magnetic resonance spectroscopy and “Cl MS” refers to chemicalionization mass spectrometry.

[0048] A: Ethyl (3-chlorophenoxy)acetate (10)

[0049] Acetone (320 ml), 75 g (450 mmol) of ethyl bromoacetate, and 40.0g (310 mmol) of 3-chlorophenol were mixed together, then 69.8 g (505mmol) of potassium carbonate was added. The mixture was mechanicallystirred and heated to reflux for 4 h, and after cooling to roomtemperature, was poured into 350 mL of ethyl acetate. To this was thencautiously added 400 mL of 1 M HCl, taking care to avoid excess foaming.The layers were separated and the aqueous layer was extracted withportions of ethyl acetate (3×200 mL). The combined organic layers weredried over MgSO₄, filtered, concentrated, and the resulting solid wasrecrystallized from hexane to afford 58 g (87%) of 10 as a white solid,m.p.=39-40° C. ¹H NMR δ 7.20-7.08 (m,1 H), 6.95-6.82 (m, 2 H), 6.75-6.70(m, 1 H), 4.53 (s, 2 H), 4.21 (q, J =7.2 Hz, 2 H), 1.23 (t, J=7.2 Hz, 3H).

[0050] B: Dimethyl [3-(3-chlorophenoxy)-2-oxoprop-1-yl]phosphonate (11)

[0051] To 20.6 g (166 mmol, 238 mol %) of dimethyl methylphosphonate in110 mL of THF at −78° C. was added dropwise 65 mL (162 mmol, 232 mol %)of a 2.5 M solution of n-BuLi in hexanes. After addition was complete,the mixture was stirred for an additional 1 h, after which 15.0 g (69.9mmol) of aryloxyester 10 in 40 mL of THF was added dropwise. Thereaction was stirred for 1 h and then quenched by the addition of 100 mLof saturated NH₄Cl. The mixture was poured into 200 mL of a {fraction(1/1)} mixture of saturated NaCl/ethyl acetate, layers were separated,and the aqueous layer was further extracted with ethyl acetate (2×100mL). Combined organic layers were dried over MgSO_(4,) filtered, andconcentrated, to afford 20.5 g (100%) of 11 as a viscous oil. ¹H NMR δ7.22 (t, J=8.1 Hz, 1 H), 7.05-6.90 (m, 2 H), 6.85-6.78 (m, 1 H), 4.72(s, 2 H), 3.84 (s, 3 H), 3.78 (s, 3 H), 3.27 (d, J=22.8 Hz, 2 H).

[0052] C: (3aR, 4 R, 5 R,6aS)-5-(Benzoyloxy)-4-[(E)-4-(3-chlorophenoxy)-3-oxo-1-butenyl]-hexahydro-2H-cyclopenta[b]furan-2-one (13)

[0053] Phosphonate 11 of bissilane (20.5 g, 70.0 mmol), 2.6 g (62 mmol)of LiCl, and 200 mL of THF were mixed together at 0° C. and 6.10 g (60.4mmol) of NEt₃ was added. Aldehyde 12 (14.0 g, 51.1 mmol) dissolved in 50mL of CH₂Cl₂ was then added dropwise. After 1 h, the reaction was pouredinto 200 mL of a {fraction (1/1)} mixture of saturated NH₄Cl/ethylacetate, the layers were separated, and the aqueous layer was extractedwith ethyl acetate (2×100 mL). Combined organic layers were dried overMgSO₄, filtered, concentrated, and the residue was chromatographed onsilica gel eluting with ethyl acetate/hexanes, 3/2, to afford 16.2 g(72%) of 13 as a white crystalline solid, m.p.=101.0-102.0° C. ¹H NMR δ8.0-7.9 (m, 2 H), 7.62-7.52 (m, 1 H), 7.50-7.38 (m, 2 H), 7.18 (t, J=8.2Hz, 1 H), 7.0-6.82 (m, 3 H), 6.75-6.70 (m, 1 H), 6.54 (d, J=15.1 Hz, 1H), 5.32 (q, J=6.2 Hz, 1 H), 5.12-5.05 (m, 1 H), 4.66 (s, 2 H), 3.0-2.8(m, 3 H), 2.7-2.2 (m, 3 H).

[0054] D: (3aR, 4 R, 5 R, 6aS)-5-(Benzoyloxyy-4-[(E)-(3R)-4-(3-chlorophenoxy)-3-hydroxy-1-butenyl]-hexahydro-2H-cyclopenta[b]furan-2-one (14)

[0055] To a solution of 9.70 g (22.0 mmol) of enone 13 in 60 mL of THFat −23° C. was added dropwise a solution of 11.1 g (34.6 mmol) of(−)-B-chlorodiisopino-campheylborane in 30 mL of THF. After 4 h, thereaction was quenched by the dropwise addition of 5 mL of methanol andthen warmed to room temperature. After pouring into 200 mL of a 2/1mixture of ethyl acetate/saturated NH₄Cl, the layers were separated, andthe aqueous phase was extracted with ethyl acetate (2×100 mL). Combinedorganic layers were dried over MgSO₄, filtered, concentrated, and theresidue was chromatographed on silica gel eluting with ethylacetate/hexanes, 3/2, to afford 4.7 g (48%) of 14 as a white solid, m.p. 101.0-102.0° C. ¹H NMR δ 8.05-7.95 (m, 2 H), 7.62-7.40 (m, 3 H), 7.18(t, J=8.0 Hz, 1 H), 7.0-6.92 (m, 1 H), 6.85 (t, J=2.1 Hz, 1 H),6.77-6.70 (m, 1 H), 5.85 (d of d, J=6.2, 15.5 Hz, 1 H), 5.72 (d of d,J=4.5, 15.5 Hz, 1 H), 5.30 (q, J=5.8 Hz, 1 H), 5.12-5.04 (m, 1 H),4.58-4.48 (m, 1 H), 3.92 (d of d, J=3.5, 9.3 Hz, 1 H), 3.80 (d of d,J=7.3, 9.4 Hz, 1 H), 2.9-2.2 (m, 8 H).

[0056] E: (3aR, 4 R, 5 R, 6aS)-4-[(E)-(3R)-4-(3-Chlorophenoxy)-3-(tetrahydropyran-2-yloxy)-1-butenyl]-5-(tetrahydropyran-2-yloxy)-hexahydro-2 H-cyclopenta[b]furan-2-one(16)

[0057] To a mixture of 5.1 g (11.5 mmol) of 14 in 200 mL of methanol wasadded 1.7 g (12 mmol) of K₂CO₃. After 1 h, the mixture was poured into100 mL of 0.5 M HCl and extracted with ethyl acetate (3×100 mL). Thecombined organic layers were washed successively with water (2×100 mL)and saturated NaCl (2×100 mL). The organic layer was dried over MgSO₄,filtered, and concentrated to afford 4.85 g of crude diol 15, which wasused in the next step without further purification.

[0058] To a mixture of 4.85 g of crude 15 and 2.4 g (28 mmol) of3,4-dihydro-2 H-pyran in 75 mL of CH₂Cl₂ at 0° C. was added 370 mg (1.9mmol) of p-toluenesulfonic acid monohydrate. After stirring for 45 min,the reaction was poured into 40 mL of saturated NaHCO₃, layers wereseparated, and the aqueous layer was extracted with CH₂Cl₂ (2×40 mL).The combined organic layers were dried over MgSO₄, filtered, andconcentrated. The residue was chromatographed on silica gel eluting with40% ethyl acetate in hexanes, to afford 6.0 g (100%) of 16 as an oil. ¹HNMR (CDCl₃)δ (characteristic peaks only) 7.25-7.14 (m, 1 H), 6.95-6.87(m, 2 H), 6.83-6.72 (m, 1 H), 5.8-5.4 (m, 4 H), 5.1-4.8 (m, 2 H).

[0059] F: (13E)-(9 S, 11 R 15R)-11,15-Bis(tetrahydropyran-2-yloxy)-16-(3-chlorophenoxy)-2,3,4,5,6,17,18,19,20-nonanor-9-triethylsilyloxy-13-prostenol Triethylsilyl Ether (18)

[0060] To a suspension of 400 mg (10.5 mmol) of lithium aluminum hydridein 20 mL of THF at 0° C. was added dropwise a solution of 4.5 g (8.8mmol) of lactone 16 in 20 mL of THF. After 1 h at 0° C. the mixture wascautiously poured into 100 mL of a {fraction (1/1)} mixture of ice-coldsaturated NH₄Cl/ethyl acetate. The layers were separated, and theaqueous layer was extracted with ethyl acetate (2×50 mL). The combinedorganic layers were dried over MgSO₄, filtered, and concentrated toafford 4.5 g (100%) of diol 17 which was used in the next step withoutfurther purification.

[0061] Triethylsilyl chloride (3.0 g, 20 mmol) was added to a mixture of4.5 g (8.8 mmol) of crude 17, 40 mL of DMF, 1.85 g (27.0 mmol) ofimidazole, and 310 mg (2.5 mmol) of 4-(dimethylamino)pyridine. After 2h, the reaction was poured into 100 mL of a {fraction (1/1)} mixture ofethyl acetate/saturated NH₄Cl, layers were separated, and the aqueouslayer was extracted with ethyl acetate (2×25 mL). The combined organiclayers were washed with water (3×25 mL), dried over MgSO₄, andconcentrated. The residue was chromatographed on silica gel eluting with20% ethyl acetate in hexane to afford 5.2 g (80%) of 18. ¹H NMR (CDCl₃)δ (characteristic peaks only) 7.22-7.12 (m, 1 H), 6.95-6.88 (m, 2 H),6.83-6.71 (m, 1 H), 5.8-5.4 (m, 4 H), 5.1-4.8 (m, 2 H), 1.0-0.85 (m, 18H), 0.7-0.5 (m, 12 H).

[0062] G: (13E)-(9 S, 11 R, 15R)-11,15-Bis(tetrahydropyran-2-yloxy)-16-(3-chlorophenoxy)-2,3,4,5,6,17,18,19,20-nonanor-9-triethylsilyloxy-13-prostenal (19)

[0063] To a mixture of 1.6 g (12.6 mmol) of oxalyl chloride and 15 mL ofCH₂Cl₂ at −78° C. was added dropwise a solution of 1.54 g (19.7 mmol) ofDMSO in 2 mL of CH₂Cl₂. After 10 min, 4.6 g (6.2 mmol) of bissilane 18in 8 mL of CH₂Cl₂ was added dropwise. After 95 min, 3.0 g (30 mmol) ofNEt₃ was added. The mixture was then warmed to room temperature andpoured into 70 mL of saturated NH₄Cl. The solution was extracted with ofCH₂Cl₂ (3×70 mL) and the combined organic layers were dried over MgSO₄,filtered, and concentrated. The residue was chromatographed on silicagel eluting with 20% ethyl acetate in hexane to afford 2.06 g (53%) of19 as well as 1.5 g (26%) recovered 18. ¹H NMR (CDCl₃) δ (characteristicpeaks only) 9.78 (t, J=1.4 Hz, 1 H), 7.22-7.12 (m, 1 H), 6.95-6.88 (m, 2H), 6.83-6.71 (m, 1 H), 5.8-5.4 (m, 4 H) 5.1-4.8 (m, 2 H), 1.0-0.85 (m,18 H), 0.7-0.5 (m, 12 H).

[0064] H: (5Z, 13E)-(9 S, 11 R, 15R)-11,15-Bis(tetrahydropyran-2-yloxy)-16-(3-chloro-phenoxy)-2,3,4,17,18,19,20-heptanor-9-triethylsilyloxy-5,13-prostadienoic Acid Methyl Ester (21)

[0065] To a solution of 1.35 g (4.24 mmol) of phosphonate 20 and 2.60 g(9.84 mmol) of 18-crown-6 in 20 mL of THF at −78° C. was added dropwise6.9 mL (3.45 mmol) of a 0.5 M solution of potassium hexamethyidisilazanein toluene. After stirring for 15 min, a solution of 1.65 g (2.64 mmol)of aldehyde 19 in 20 mL of THF was added dropwise. One hour later, themixture was poured into 100 mL of saturated NH₄Cl/ethyl acetate,{fraction (1/1)}, layers were separated, and the aqueous layer wasextracted with ethyl acetate (3×30 mL). The combined organic layers weredried over MgSO₄, filtered, concentrated and the residue waschromatographed on silica gel eluting with 20% ethyl acetate in hexaneto afford 1.135 g (63%) of 21. ¹H NMR (CDCl₃)δ (characteristic peaksonly) 7.22-7.11 (m, 1 H), 6.97-6.86 (m, 2 H), 6.85-6.75 (m, 1 H),6.4-6.2 (m, 1 H), 5.8-5.32 (m, 3 H), 3.66 (s, 3 H).

[0066] I: (5Z, 13E)-(9 S, 11 R, 15R)-11,15-Bis(tetrahydropyran-2-yloxy)-16-(3-chloro-phenoxy)-2,3,4,17,18,19,20-heptanor-9-triethylsilyloxy-5, 13-prostadien-1-ol (22)

[0067] To a solution of 850 mg (1.25 mmol) of ester 21 in 10 mL of THFat 0° C. was added 2.4 mL (3.6 mmol) of a 1.5 M solution ofdiisobutylaluminum hydride in toluene. After 1 h, the mixture was pouredinto 20 mL of saturated NH₄Cl and was extracted with ethyl acetate (3×20mL). Combined organic layers were dried over MgSO₄, filtered, andconcentrated down to 800 mg (98%) of 22 as an oil. ¹H NMR (CDCl₃) ä(characteristic peaks only) 7.25-7.15 (m, 1 H), 6.97-6.90 (m, 2 H),6.86-6.75 (m, 1 H), 5.81-5.41 (m, 4 H).

[0068] J:(5Z, 13E)-(9 S, 11 R, 15R)-11,15-Bis(tetrahydropyran-2-yloxy)-16-(3-chloro-phenoxy)-3-oxa-17,18,19,20-tetranor-9-triethylsilyloxy-5,13-prostadienoic Acid Isopropyl Ester (23)

[0069] To a solution of 415 mg (6.37 mmol) of alcohol 22 in 4 mL of THFat −78° C. was added dropwise 0.35 mL (0.87 mol) of a 2.5 M solution ofn-BuLi in hexane. After 15 min, this solution was transferred viasyringe to a −78° C. solution of 195 mg (1.08 mmol) of isopropylbromoacetate in 2 mL of THF. The mixture was kept at −78° C. for 40 min,warmed to room temperature overnight, and then poured into 20 mL of a{fraction (1/1)} mixture of saturated NH₄Cl/ethyl acetate. Layers wereseparated, and the aqueous layer was extracted with ethyl acetate (2×10mL). The combined organic layers were dried over MgSO₄, filtered,concentrated, and the residue was chromatographed on silica gel (20%ethyl acetate in hexane) to afford 242 mg (53%) of 23 as an oil. ¹H NMR(CDCl₃)δ (characteristic peaks only) 7.24-7.15 (m, 1 H), 6.97-6.90 (m, 2H), 6.86-6.75 (m, 1 H), 5.81-5.41 (m, 4 H), 1.57 (d, J=5.7 Hz, 6 H).

[0070] K:(5Z, 13E)-(9 S, 11 R, 15R)-16-(3-Chlorophenoxy)-3-oxa-17,18,19,20-tetranor-9,11,15-trihydroxy-5,13-prostadienoic Acid Isopropyl Ester (5)

[0071] To a solution of 230 mg (0.32 mmol) of silane 23 in 5 mL of THFat room temperature was added 0.33 mL (0.33 mmol) of a 1 M solution ofBU₄NF in THF. After 20 min, the reaction was poured into 4 mL ofsaturated NH₄Cl and was extracted with ethyl acetate (4×5 mL). Thecombined organic layers were dried over MgSO₄, filtered, concentrated,and the residue was chromatographed on silica gel (ethyl acetate/hexane,{fraction (1/1)}), to afford 126 mg (65%) of desilylated compound 24.

[0072] To 120 mg of 24 in 5 mL of methanol was added 0.4 mL of 2 M HCl.After 1 h, the mixture was added to 3 mL of saturated NaHCO₃, and theresulting mixture was extracted with ethyl acetate (3×8 mL). Combinedorganic layers were dried over MgSO₄, filtered, concentrated. Theresulting residue was then chromatographed on silica gel eluting withethyl acetate to afford 54 mg (56%) of 5. ¹³C NMR (CDCl₃)δ 169.92 (C),159.26 (C), 135,13 (CH), 134.95 (CH), 134.81 (C), 124.93 (CH), 121.22(CH), 115.06 (CH), 113.08 (CH), 77.75 (CH), 72.02 (CH), 71.94 (CH₂),70.76 (CH₂), 68.77 (CH), 67.78 (CH₂), 66.50 (CH₂), 55.46 (CH), 49.93(CH), 42.47 (CH₂), 25.85 (CH₂), 21.75 (CH₃). Cl MS, m/z calcd. forC₂₄H₃₄O₇Cl₁ (MH⁺), 469.1993, found 469.1993.

[0073] A:(3aR, 4 R, 5 R, 6aS)-5-Hydroxy-4-[(3R)-4-(3-trifluoromethylphenoxy)-3-hydroxy-1-butyl ]-hexahydro-2H-cyclopenta[b]furan-2-one (26)

[0074] A mixture of 1.2 g (3.2 mmol) of diol 25 (for synthesis of diol25, see U.S. Pat. No. 4,321,275) and 0.05 g of 10% (wt/wt) Pd/C in 20 mLof methanol was hydrogenated at 30 psi for 1.5 hours. After filtrationthrough a short pad of Celite® concentration afforded 1.2 g (100%)of 26as a colorless oil. ¹H NMR (CDCl₃) δ 7.44 (m, 2 H), 7.12 (m, 2 H), 4.95(dt, 1 H), 4.15-3.80 (m, 4 H), 2.82 (dd, J=10.8, 1 H), 2.55 (m, 2 H),2.3 (m, 1 H), 2.1-1.3 (m, 6 H).

[0075] B:(3aR, 4 R, 5 R, 6aS)-5-(Tetrahydropyran-2-yloxy)-4-[(3R)-4-(3-trifluoromethylphenoxy)-3-(tetrahydropyran-2-yloxy)-1-butyl]-hexahydro-2H-cyclopenta[b]furan-2-one (27)

[0076] A mixture of 1.2 g (3.2 mmol) of diol 26 and 0.05 g ofp-toluenesulfonic acid monohydrate in 100 mL of CH₂Cl₂ at 0° C. wastreated with 3,4-dihydro-2 H-pyran (1.1 ml, 12 mmol) and the solutionwas stirred for 2 h at 0° C. After pouring into saturated NaHCO₃, phaseswere separated and the organic layer was dried over MgSO₄, filtered,concentrated, and purified by chromatography on silica gel ({fraction(1/1)}, hexanes/EtOAc) to afford 1.1 g of 27 as a clear, colorless oil.¹ H NMR (CDCl₃)δ 8.04 (dd, J=7.0, 1.6, 1 H), 7.44 (m, 2 H), 7.12 (m, 1H), 4.95 (dt, 1 H), 4.8 (m, 1 H), 4.7 (m, 2 H), 4.15-3.80 (m, 4 H), 3.5(m, 2 H), 2.82 (dd, J=10.8,1 H), 2.55 (m, 2 H), 2.3 (m, 1 H), 2.1-1.3(m, 6 H).

[0077] C: (5Z)-(9 S, 11 R, 15 R)-11,15-Bis(tetrahydropyran-2-yloxy)-9-hydroxy-17,18,19,20-tetranor-16-(3-trifluoromethylphenoxy)-5-prostenoic Acid Isopropyl Ester (31)

[0078] To a solution of 2.1 g (3.9 mmol) of 27 in 100 mL of THF at −78°°C. was added 3.9 mL (5.8 mmol) of a 1.5 M solution of diisobutyaluminumhydride in toluene. The solution was stirred for 2 h, then quenched bythe sequential addition of 0.4 mL of isopropanol at −78° C. followed by0.4 mL of water at 23° C. Volatiles were removed under reduced pressureand the aqueous solution was extracted with Et₂O/EtOAc ({fraction(1/1)}). Organic extracts were dried over MgSO₄, filtered, andconcentrated to furnish 1.9 g of lactol 28.

[0079] To a 250 mL 3-necked round bottom flask equipped with amechanical stirrer and a thermometer were added anhydrous DMSO (100 mL)and NaH (80% dispersion in mineral oil; 0.48 g, 16 mmol). The mixturewas heated to 75° C. (internal) for 30 min, after which it was allowedto cool to room temperature for 1 h. Phosphonium bromide 29 (3.5 g, 8mmol) was then added. After stirring for 30 minutes, 1.9 g (3.5 mmol) oflactol 28 in 50 mL of DMSO was added, and the resulting solution washeated to 50° C. for 2 h and then brought to room temperature for 16 h.The solution was poured into 100 mL of water and approximately 2 mL of50% NaOH added. The aqueous phase was extracted with ether (3×100 mL),then made acidic (pH=5.5) by the addition of a 10% citric acid solution,and extracted with Et₂O/hexanes, 2/1 (3×100 mL). The combined organicextracts were dried over MgSO₄, filtered, and concentrated to afford 1.9g of 30 as a colorless oil.

[0080] To 1.9 g of carboxylic acid 30 dissolved in 10 mL acetone wasadded 0.95 g (6.0 mmol) of DBU and 1.0 g (6.1 mmol) of isopropyl iodideat 23° C. After 16 h, the solution was poured into 100 mL of water andextracted with 100 mL of EtOAc. The organic extract was dried overMgSO₄, filtered, concentrated, and purified by silica gel chromatography(3/2, hexanes/EtOAc) to afford 1.9 g of isopropyl ester 31 as acolorless oil. ¹H NMR (CDCl₃)δ 7.44 (t, 1 H), 7.12 (d, 1 H), 7.12 (dd, 2H), 5.5-5.3 (m, 2 H), 4.99 (heptet, 1 H), 4.15-3.80 (m, 4 H), 2.82 (dd,J=10.8,1 H), 2.55 (m, 2 H), 2.3 (m, 1 H), 2.1-1.3 (m, 24 H), 1.23 (s, 3H), 1.20 (s, 3 H).

[0081] D: (5Z)-(9 S, 11 R, 15R)-17,18,19,20-Tetranor-16-(3-trifluoromethylphenoxy)-9,11,15-trihydroxy-5-prostenoic Acid Isopronyl Ester (6)

[0082] Ester 31 (1.9 g, 2.8 mmol) was dissolved in 14 mL of a mixture ofAcOH/THF/H₂O (4/2/1) and the solution was heated to 50° C. for 1 h,allowed to cool to 23° C., poured into a saturated solution of NaHCO₃,and extracted with Et₂O (2×100 mL) and EtOAc (100 mL). The combinedorganic extracts were dried over MgSO₄, filtered, concentrated, andpurified by silica gel chromatography ({fraction (1/1)}, hexanes/EtOAc)to furnish 0.5 g of triol 6 as a clear, colorless oil. ¹ NMR (CDCl₃) δ7.44 (t, J=7.8, 1 H), 7.12 (dd, J=7.8, 2.0,1 H), 7.12 (ddd, J=15.6, 7.2,2.0, 2 H), 5.5-5.3 (m, 2 H), 4.99 (heptet, J=6.3, 1 H), 4.15-3.80 (m, 4H), 3.2 (d, 1 H), 2.95 (s, 1 H), 2.82 (dd, J=10.8,1 H), 2.75 (d, J=5.9,1 H), 2.55 (m, 2 H), 2.3 (m, 1 H), 2.1-1.3 (m, 24 H), 1.23 (s, 3 H),1.20 (s, 3 H), ¹³C NMR (CDCl₃)δ 173.5,158.7,132.1, 131.5,130.0,129.5,129.2,123.3,120.8, 117.7,117.6,111.4, 111.4,78.6,74.4, 72.4, 69.9, 67.6,52.6, 51.7,42.5, 34.0, 31.5, 29.4, 26.8,26.6, 24.9, 21.7.

[0083] A:(5Z, 13E)-(9 S, 11 R, 15R)-11,15-Bis(tetrahydropyran-2-yloxy)-16-(3-chlorophenoxy)-9-hydroxy-17,18,19,20-tetranor-5,13-prostadienoic Acid Isopropyl Ester (34)

[0084] A 1.5 M solution of diisobutylaluminum hydride in toluene (10 mL,15 mmol) was added dropwise to a solution of 5.8 g (11.4 mmol) oflactone 16 in 55 mL of THF at −78° C. After 1 h, 10 mL of methanol wasadded dropwise, and the mixture was stirred for 10 min at −78° C. beforebeing warmed to room temperature. The mixture was then poured into 100mL of a {fraction (1/1)} solution of saturated aqueous potassium sodiumtartrate/ethyl acetate and stirred. After separating layers, the aqueousphase was extracted with ethyl acetate (2×40 mL). Combined organiclayers were dried over MgSO₄, filtered, concentrated, and purified bysilica gel chromatography (3/2, ethyl acetate/hexane), to afford 4.4 g(76%) of lactol 33, which was used immediately in the next step.

[0085] A 1 M solution of potassium t-butoxide in THF (50.0 ml) was addeddropwise to 12.1 g (27.3 mmol) of phosphonium salt 29 in 100 mL of THFat 0° C. After 30 min, a solution of 4.4 g (8.6 mmol) of lactol 33 in 20mL of THF was added dropwise, and the mixture was stirred at roomtemperature overnight. The solution was then poured into 150 mL of a{fraction (1/1)} mixture of ethyl acetate/saturated NH₄Cl. Layers wereseparated and the aqueous layer was extracted with ethyl acetate (2×100mL). Combined organic layers were dried over MgSO₄, filtered,concentrated, and the residue was redissolved in 80 mL of acetone. Tothis was added 6.5 g (45 mmol) of DBU followed by 7.3 g (43 mmol) ofisopropyl iodide. After stirring overnight, the reaction was poured into100 mL of a {fraction (1/1)} mixture of ethyl acetate/saturated NH₄Cl.Layers were then separated and the aqueous phase was further extractedwith ethyl acetate (2×100 mL). The combined organic layers were driedover MgSO₄, filtered, concentrated, and purified by silica gelchromatography (40% ethyl acetate in hexane) to afford 2.92 g (53% fromlactone 16) of ester 34.

[0086] B: (5Z, 13E)-(9 S, 11 R, 15 R)-16-(3-Chlorophenoxy)-17,18,19,20-tetranor-9,11,15-trihydroxy-5,13-prostadienol (7)

[0087] A solution of 500 mg (0.79 mmol) of 34 in 10 mL of THF was addeddropwise to 61 mg (1.60 mmol) of lithium aluminum hydride in 20 mL ofTHF at 0° C. After 40 min, the reaction was carefully poured into 15 mLof saturated NH₄Cl, and the mixture was then extracted with ethylacetate (3×40 mL). Combined organic layers were dried over MgSO₄,filtered, and concentrated to afford 500 mg of crude 35.

[0088] To a solution of 500 mg of 35 in 20 mL of methanol was added 0.5mL of 2 M HCl. After 1 h, the reaction was quenched with 20 mL ofsaturated NaHCO₃ and the mixture was extracted with ethyl acetate (4×30mL). The combined organic layers were dried over MgSO₄, filtered, andconcentrated. Silica gel chromatography (EtOAc) provided 101 mg (31%from 34) of 7. ¹³C NMR (CDCl₃)δ 159.27 (C), 135.44 (CH), 134.82 (C),130.64 (CH), 130.26 (CH), 128.23 (CH), 121.25 (CH), 115.07 (CH), 113.08(CH), 77.35 (CH), 72.35 (CH), 71.90 (CH₂), 70.89 (CH), 62.22 (CH₂),55.40 (CH), 49.87 (CH), 42.79 (CH₂), 31.83 (CH₂), 26.77 (CH₂), 25.60(CH₂), 25.33 (CH₂). Cl MS m/z calcd for C₂₂H₃₂O₅Cl₁(MH⁺) 411.1938, found411.1938.

[0089] A: (3aR, 4 R, 5 R, 6aS)-4-[(3R)-4-(3-Chlorophenoxy)-3-hydroxybutyl]-5-hydroxy-hexahydro-2H-cyclopenta[b]furan-2-one (37):

[0090] A mixture of 2.4 g (5.4 mmol) of 14 and 250 mg of 10% (wt/wt)Pd/C in 35 mL of ethyl acetate was hydrogenated at 40 psi for 1 h. Afterfiltration through a short pad of Celite®, the filtrate was evaporateddown to 2.3 g (100%) of hydrogenated product 36.

[0091] The crude benzoate 36 was dissolved in 25 mL of methanol, and 610mg (4.4 mmol) of K₂CO₃ was added. After 3.5 h, the mixture was pouredinto 100 mL of water/ethyl acetate ({fraction (1/1)}). Layers wereseparated, and the aqueous phase was further extracted with ethylacetate (2×50 mL). The combined organic layers were dried over MgSO₄,filtered and concentrated. Silica gel chromatography (EtoAc) provided1.50 g (82%) of 37 as a white solid, m.p.=102.0-103.5° C. ¹H NMRδ 7.22(t, J=8.2 Hz, 1 H), 7.0-6.94 (m, 1 H), 6.91-6.88 (t, J=2.1 Hz, 1 H),6.83-6.77 (m, 1 H), 4.97 (dt, J=3.0, 8.3 Hz, 1 H), 4.12-3.91 (m, 3 H),3.82 (dd, J=7.4, 9.0 Hz, 1 H), 2.85 (dd, J=8.0, 16.5Hz, 1 H), 2.6-1.4(m, 11 H).

[0092] B: (3aR, 4 R, 5 R, 6aS)-4-[(3R)-4-(3-Chlorophenoxy)-3-(tetrahydropyran-2-yloxy)butyl]-5-(tetrahydropyran-2-yloxy)-hexahydro-2H-cyclopenta[b]furan-2-one (38)

[0093] Diol 37 (3.4 g, 10 mmol) and 2.2 g (26 mmol) of 3,4-dihydro-2H-pyran were dissolved in 80 mL of CH₂Cl₂, and 240 mg (1.3 mmol) ofp-toluenesulfonic acid monohydrate was added at 0° C. After 1 h, thereaction was poured into 50 mL of saturated NaHCO₃ and the mixture wasextracted with CH₂Cl₂ (3×40 mL). The combined organic layers were driedover MgSO₄, filtered, concentrated, and the residue was chromatographedon silica gel (hexane/ethyl acetate, {fraction (1/1)}) to afford 4.5 g(87%) of bis-THP ether 38.

[0094] C:(5Z)-(9S, 11R,15R)-11,15-Bis(tetrahydropyran-2-yloxy)-16-(3-chlorophenoxy)-9-hydroxy-17,18,19,20-tetranor-5-prostenoic Acid Isopropyl Ester (41)

[0095] A 1.5 M solution of diisobutylaluminum hydride in toluene (1.8mL, 2.7 mmol) was added to the solution 1.05 g (2.06 mmol) of 38 in 10mL of THF at −78° C. After 1 h, 4 mL of methanol was added and themixture was warmed to 25° C., then poured into 40 mL of ethylacetate/saturated aqueous potassium sodium tartrate ({fraction (1/1)}).Layers were separated and the aqueous phase was further extracted withethyl acetate (3×30 mL). The combined organic layers were then driedover MgSO₄, filtered, concentrated, and the residue was chromatographedon silica gel (ethyl acetate) to afford 740 mg (70%) of lactol 39.

[0096] A 1.5 M solution of potassium t-butoxide in THF (8.6 mL, 8.6mmol) was added dropwise to a mixture of 15 mL of THF and 1.92 g (4.33mmol) of phosphonium salt 29 at 0° C. After stirring for 1 h, a solutionof 740 mg (1.45 mmol) of lactol 39 in 5 mL of THF was added dropwise,and the reaction was allowed to warm to 25° C. overnight. The mixturewas then poured into 100 mL of ethyl acetate/saturated NH₄Cl ({fraction(1/1)}). Layers were separated, and the aqueous phase was furtherextracted with ethyl acetate (2×70 mL). Combined organic layers weredried over MgSO₄, filtered, and concentrated to afford 1.6 g of crudeacid 40.

[0097] Crude acid 40 (1.6 g) was dissolved in 11 mL of acetone andcooled to 0° C., then 850 mg (5.6 mmol) of DBU was added dropwise to thesolution. The resulting mixture was stirred for 15 min at 0 ° C. and 30min at 25° C., after which 850 mg (5.0 mmol) of isopropyl iodide wasadded. The reaction was stirred overnight and poured into 100 mL ofethyl acetate/saturated NH₄Cl ({fraction (1/1)}). Layers were separated,and the aqueous phase was further extracted with ethyl acetate (2×50mL). Combined organic layers were dried over MgSO₄, filtered andconcentrated. The resulting residue was purified by silica gelchromatography (ethyl acetate/hexanes, 3/2) to afford 560 mg (61% fromlactol 39) of isopropyl ester 41.

[0098] D:(5Z)-(9 S 11 R, 15R)-16-(3-Chlorophenoxy)-17,18,19,20-tetranor-9,11,15-trihydroxy-5-prostenolPivaloate (8)

[0099] A solution of 400 mg (0.63 mmol) of 41 42in 5 mL of THF was addeddropwise to a suspension of 35 mg (0.92 mmol) of lithium aluminumhydride in 5 mL of THF at 0° C. After 2 h, the reaction was poured into50 mL of a {fraction (1/1)} mixture of ethyl acetate/saturated NaHCO₃.The layers were then separated, and the aqueous phase was extracted withethyl acetate (2×2 mL). Combined organic layers were dried over MgSO₄,filtered, and concentrated. The resulting residue was purified by silicagel chromatography (ethyl acetate) to afford 350 mg (95%) of diol 42.

[0100] Pivaloyl chloride (90 mg, 0.75 mmol) was added to a mixture of350 mg (0.60 mmol) of 42, 60 mg (0.76 mmol) of pyridine, 22 mg (0.18mmol) of 4-(dimethylamino) pyridine, and 7 mL of CH₂Cl₂. After 1.5 h,the mixture was poured into 30 mL of saturated NH₄Cl/ethyl acetate({fraction (1/1)}). Layers were then separated and the aqueous phase wasextracted with ethyl acetate (2×20 mL). The combined organic layers weredried over MgSO₄, filtered, concentrated, and purified by silica gelchromatography (ethyl acetatelhexane, 3/2) to afford 370 mg (93%) ofpivaloate 43.

[0101] Water (approximately 10 drops) and concentrated HCl(approximately 3 drops) were added to a solution of 370 mg (0.56 mmol)of 43 in 5 mL of methanol. After stirring overnight, the reaction wasquenched by the addition of 20 mL of saturated NaHCO₃, and the mixturewas extracted with ethyl acetate (3×20 mL). The combined organic layerswere dried over MgSO₄, filtered, and concentrated. The residue waschromatographed on silica gel (ethyl acetatelhexane, 3/2), to afford 165mg (59%) of triol 8. ¹³C NMR (CDCl₃) δ178.77 (C), 159.27 (C), 134.80(C), 130.20 (CH), 128.62 (CH), 121.19 (CH), 114.97 (CH), 112.97 (CH),78.50 (CH), 74.46 (CH), 72.31 (CH₂), 69.86 (CH), 64.16 (CH₂), 52.53(CH), 51.67 (CH), 42.50 (CH₂), 31.51 (CH₂), 29.40 (CH₂), 28.10 (CH₂),27.12 (CH₃), 26.77 (CH₂), 26.65 (CH₂), 25.77 (CH₂). Cl MS, m/z calcd forC₂₇H₄₁O₆Cl₁ (MH⁺), 497.2670, found 497.2656

[0102] Included within the scope of the present invention are theindividual enantiomers of the title compounds, as well as their racemicand non-racemic mixtures. The individual enantiomers can beenantioselectively synthesized from the appropriate enantiomericallypure or enriched starting material by means such as those describedbelow. Alternatively, they may be enantioselectively synthesized fromracemic/non-racemic or achiral starting materials. (Asymmetric Synthesisby J. D. Morrison and J. W. Scott, Ed., Academic Press Publishers: NewYork, 1983-1985 (five volumes published over a three year span withchapters contributed by about two dozen authors) and Principles ofAsymmetric Synthesis by R. E. Gawley and J. Aube, Ed., ElsevierPublishers: Amsterdam, 1996). They may also be isolated from racemic andnon-racemic mixtures by a number of known methods, e.g. by purificationof a sample by chiral HPLC (A Practical Guide to Chiral Separations byHPLC, G. Subramanian, Ed., VCH Publishers: New York, 1994; ChiralSeparations by HPLC, A. M. Krstulovic, Ed., Ellis Horwood Ltd.Publishers, 1989), or by enantioselective hydrolysis of a carboxylicacid ester sample by an enzyme (Ohno, M.; Otsuka, M. Organic Reactions,volume 37, page 1 (1989)). Those skilled in the art will appreciate thatracemic and non-racemic mixtures may be obtained by several means,including without limitation, nonenantioselective synthesis, partialresolution or even mixing samples having different enantiomeric ratios.Also included within the scope of the present invention are theindividual isomers substantially free of their respective enantiomers.

EXAMPLE 5

[0103] PGF_(2α) analogues are known to contract the iris sphincter ofcats and this assay is a generally accepted reference for activity. Forthis reason, the pupil diameter of cats may be used to define theactivity of PGF_(2α) analogues and, as demonstrated by Stjernschantz andResul (Drugs Future, 17:691-704 (1992)), predict the IOP-loweringpotency.

[0104] Compounds of the present invention were therefore screened forpupillary constriction in the cat. Data for compounds 6, 7, and 8 arepresented in Table 3, below. The response is quantitated as Area ₁₋₅values (area under the pupil diameter versus time curve from 1-5 hours),and the equivalent response dose (ED₅) is estimated from its doseresponse relationship. TABLE 3 Cat Pupil Diameter Response Compound ED₅(μg) PGF_(2α) Isopropyl Ester 0.02 Cloprostenol Isopropyl Ester 0.01 60.2 7 0.02 8 0.06

[0105] Discussion:

[0106] The two standard compounds, PGF_(2α) isopropyl ester andcloprostenol isopropyl ester, produced marked change in cat pupillarydiameter, displaying ED₅ values of 0.02 and 0.01 μg, respectively.Compound 7 (cloprostenol-1-ol) and compound 8(13,14-dihydrocloprostenol-1-ol pivaloate), displayed nearly equivalentpotency. 13,14-Dihydrofluprostenol isopropyl ester (compound 6) wasapproximately one order of magnitude less potent, with an ED₅ of 0.2 μg.

EXAMPLE 6

[0107] In the study presented below, compound 6 (Table 2, above) wastested for IOP-lowering effect in cynomolgus monkey eyes.

[0108] The right eyes of the cynomolgus monkeys used in this study werepreviously given laser trabeculoplasty to induce ocular hypertension inthe lasered eye. Animals had been trained to sit in restraint chairs andconditioned to accept experimental procedures without chemicalrestraint. IOP was determined with a pneumatonometer after light cornealanesthesia with dilute proparacaine. The test protocol included afive-dose treatment regimen because of the typical delayed response toprostaglandins. The designated test formulations were administered tothe lasered right eyes, and the normal left eyes remained untreated,although IOP measurements were taken. Baseline IOP values weredetermined prior to treatment with the test formulation, and then IOPwas determined from 1 to 7 hours after the first dose, 16 hours afterthe fourth dose, and 1 to 4 hours after the fifth dose.

[0109] The equivalent response dose (ED₂₀) is estimated from the doseresponse relationship to be the dose producing a 20% peak reduction inIOP. TABLE 4 Monkey IOP Response Compound ED2₂₀ (μg) PGF_(2α) IsopropylEster 0.4 6 0.3

[0110] Discussion:

[0111] As can be seen in Table 4, compound 6, the 13,14-dihydro analogueof fluprostenol was quite potent in the monkey IOP model, producing a20% reduction at 0.3 μg. This was even more potent than the standardcompound, PGF_(2α) isopropyl ester.

EXAMPLE 7

[0112] Improvement of Optic Nerve Head Blood Flow after One-Week TopicalTreatment with Compound 1B in the Rabbit.

[0113] Purpose: A two-way crossover study design was used to compare theeffects of Compound 1B (0.004%), topically applied, and dosing vehicleon microvascular optic nerve head blood flow, blood pressure, heartrate, and acid-base balance in fifteen acepromazine-tranquilizedDutch-Belted rabbits.

[0114] Methods: Baseline measurements were taken before treatment andafter drug-free washout periods of 14 days. Microvascular optic nervehead (ONH) blood flow was measured with a fundus camera-based LaserDoppler flowmeter (LDf). Thirty microliters o a 0.004% solution ofCompound 1B or vehicle was administered in left eyes only q.d. for 7days. Experimental measurements were made 2 hours after the topical dosewas administered on day 8. A sterile 23 gauge intracatheter was insertedinto the central ear artery to monitor blood pressure and to take bloodsamples for blood pH/gas analysis.

[0115] Results: ONH blood flow was significantly increased (p<0.05) inrabbits treated with Compound 1B, when compared to the vehicle treatedgroup. The mean ±SEM percent increase from baseline was 13.4±3.9 inCompound 1B treated animals and −1.0±4.3 in vehicle treated animals.Only small non-significant changes in systemic blood pressure, heartrate, blood gas tensions and pH were present in the Compound 1Btreatment group when compared with the vehicle group. The observed meanpercent decreases in systemic arterial pH, and pO₂ and arterial pCO₂tensions were 0.07±0.09, 1.44±2.03, and 2.59±2.5, respectively.

[0116] Conclusion: One week of once a day topical ocular treatment withCompound 1B significantly increased ONH blood flow in tranquilizedDutch-Belted rabbits, while eliciting minimal systemic acid-base balancedisturbances. This suggests that the mechanism responsible for thepositive effect on the ONH vasculature involves a local ocular actionsince the blood flow increase in this study occurred without significantchanges in systemic blood pressure or arterial blood gases/pH.

EXAMPLE 8

[0117] The following Formulations 1-4 are representative pharmaceuticalcompositions of the invention for topical use in lowering of intraocularpressure. Each of Formulations 1 through 4 may be formulated inaccordance with procedures known to those skilled in the art.FORMULATION 1 Ingredient Amount (wt %) Compound 5 (Table 2) 0.002Dextran 70 0.1 Hydroxypropyl methylcellulose 0.3 Sodium chloride 0.77Potassium chloride 0.12 Disodium EDTA 0.05 Benzalkonium chloride 0.01HCl and/or NaOH pH 7.2-7.5 Purified water q.s. to 100%

[0118] FORMULATION 2 Ingredient Amount (wt %) Compound 6 (Table 2) 0.01Monobasic sodium phosphate 0.05 Dibasic sodium phosphate 0.15(anhydrous) Sodium chloride 0.75 Disodium EDTA 0.01 Benzalkoniumchloride 0.02 Polysorbate 80 0.15 HCl and/or NaOH pH 7.3-7.4 Purifiedwater q.s. to 100%

[0119] FORMULATION 3 Ingredient Amount (wt %) Compound 7 (Table 2) 0.001Dextran 70 0.1 Hydroxypropyl methylcellulose 0.5 Monobasic sodiumphosphate 0.05 Dibasic sodium phosphate 0.15 (anhydrous) Sodium chloride0.75 Disodium EDTA 0.05 Benzalkonium chloride 0.01 NaOH and/or HCl pH7.3-7.4 Purified water q.s. to 100%

[0120] FORMULATION 4 Ingredient Amount (wt %) Compound 8 (Table 2) 0.003Monobasic sodium phosphate 0.05 Dibasic sodium phosphate 0.15(anhydrous) Sodium chloride 0.75 Disodium EDTA 0.05 Benzalkoniumchloride 0.01 HCl and/or NaOH pH 7.3-7.4 Purified water q.s. to 100%

[0121] The invention has been described by reference to certainpreferred embodiments; however, it should be understood that it may beembodied in other specific forms or variations thereof without departingfrom its spirit or essential characteristics. The embodiments describedabove are therefore considered to be illustrative in all respects andnot restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description.

What is claimed is:
 1. A method of treating glaucoma and ocularhypertension which comprises topically administering to the affected eyea composition comprising a therapeutically effective amount of acombination of a carbonic anhydrase inhibitor together with a compoundhaving the absolute stereochemical structure of the following formula(IV):

wherein: R₁═H; C₁-C₁₂ straight-chain or branched alkyl; C₁-C₁₂straight-chain or branched acyl; C₃-C₈ cycloalkyl; or a cationic saltmoiety; R₂, R₃═H, or C₁-C₅ straight-chain or branched alkyl; or R₂ andR₃ taken together may represent O; X═O, S, or CH₂; - represents anycombination of a single bond, or a cis or trans double bond for thealpha (upper) chain; and a single bond or trans double bond for theomega (lower) chain; R₉═H, C₁-C₁₀ straight-chain or branched alkyl, orC₁-C₁₀ straight-chain or branched acyl; R₁₁═H, C₁-C₁₀ straight-chain orbranched alkyl, or C₁-C₁₀ straight-chain or branched acyl; Y═O; or H andOR₁₅ in either configuration wherein R₁₅ ═H, C₁-C₁₀ straight-chain orbranched alkyl, or C₁-C₁₀ straight-chain or branched acyl; and Z═Cl orCF₃; with the proviso that when R₂ and R₃ taken together represent O,then R₁≠C₁-C₁₂ straight-chain or branched acyl; and when R₂═R₃═H, thenR₁≠ a cationic salt moiety.
 2. The method of claim 1 , wherein for thecompound (IV): R₂, R₃ taken together represent O; X═CH₂; - represents acis double bond for the alpha (upper) chain and a trans double bond forthe omega (lower) chain; R₉ and R₁₁═H; and Y═OH in the alphaconfiguration and H in the beta configuration.
 3. The method of claim 2, wherein for the compound (IV): Z═CF₃.
 4. The method of claim 1 ,wherein: R₂═R₃═H, or R₂ and R₃ taken together represent O; X═O or CH₂;R₉═R₁₁═H; Y═H and OR₁₅; and R₁₅═H.
 5. The method of claim 4 , wherein:R₁═H, C₁-C₁₂ straight chain or branched alkyl or cationic salt moiety;and R₂ and R₃ taken together represent O.
 6. The method of claim 5 ,wherein the compound of formula (IV) is selected from the groupconsisting of cloprostenol, fluprostenol, 3-oxacloprostenol,13,14-dihydrofluprostenol, and their pharmaceutically acceptable estersand salts.
 7. The method of claim 4 , wherein the carbonic anhydraseinhibitor is brinzolamide.
 8. The method of claim 7 , wherein thecompound of formula (IV) is fluprostenol isopropyl ester.
 9. The methodof claim 1 , wherein between about 0.01 and about 1000 μg/eye of thecompounds of formula (IV) is administered.
 10. The method of claim 9 ,wherein between about 0.1 and about 100 μg/eye of the compound offormula (IV) is administered.
 11. The method of claim 10 , whereinbetween about 0.1 and about 10 μg/eye of the compound of formula (IV) isadministered.
 12. A topical ophthalmic composition for the treatment ofglaucoma and ocular hypertension comprising an ophthalmically acceptablecarrier and a therapeutically effective amount of a combination of acarbonic anhydrase inhibitor together with a compound having theabsolute stereochemical structure of the following formula (IV) andbeing substantially free of the enantiomer of said compound:

wherein: R₁═H; C₁-C₁₂ straight-chain or branched alkyl; C₁-C₁₂straight-chain or branched acyl; C₃-C₈ cycloalkyl; or a cationic saltmoiety; R₂, R₃═H, or C₁-C₅ straight-chain or branched alkyl; or R₂ andR₃ taken together may represent O; X═O, S, or CH₂; - represents anycombination of a single bond, or a cis or trans double bond for thealpha (upper) chain; and a single bond or trans double bond for theomega (lower) chain; R₉═H, C₁-C₁₀ straight-chain or branched alkyl, orC₁-C₁₀ straight-chain or branched acyl; R₁₁═H, C₁-C₁₀ straight-chain orbranched alkyl, or C₁-C₁₀ straight-chain or branched acyl; Y═O; or H andOR₁₅ in either configuration wherein R₁₅═H, C₁-C₁₀ straight-chain orbranched alkyl, or C₁-C₁₀ straight-chain or branched acyl; and Z═Cl orCF₃; with the proviso that when R₂ and R₃ taken together represent O,then R₁≠C₁-C₁₂ straight-chain or branched acyl; and when R₂═R₃═H, thenR₁≠ a cationic salt moiety; and with the further proviso that thefollowing compound be excluded: cyclopentaneheptenol-5-cis-2-(3-αhydroxy-4-m-chlorophenoxy-1-trans-butenyl)-3, 5dihydroxy, [1_(α), 2_(β), 3_(α),5_(α)].
 13. The composition of claim 12, wherein for the compound (IV): R₂, R₃ taken together represent O;X═CH₂; - represents a cis double bond for the alpha (upper) chain and atrans double bond for the omega (lower) chain; R₉ and R₁₁═H; and Y═OH inthe alpha configuration and H in the beta configuration.
 14. Thecomposition of claim 13 , wherein for the compound (IV): Z═CF₃.
 15. Thecomposition of claim 14 , wherein the carbonic anhydrase inhibitor isbrinzolamide and the compound of formula (IV) is travoprost.